Last racer finishes Boston Marathon in 20 grueling hours

Boston Police Commissioner William Evans, left, and Mayor Marty Walsh, center, listen as Maickel Melamed, of Venezuela, speaks during a ceremony to honor him as the last participant to finish this year's Boston Marathon Tuesday, April 21, 2015, in Boston. Melamed, 39, has a form of muscular dystrophy which severely impairs his mobility. He crossed the finish line about 20 hours after he started.(Photo: AP Photo&#47;Bill Sikes)